We have only ever given Loki Heartgard in the past. This year, given we've moved to a more wooded area, decided to treat for fleas/ticks but without meds. We use a product from the Cedarcide Store (http://www.cedarcidestore.com/ANIMALHEALTH.html) called Best Yet. So far so good (Although, I just saw that they've come out with an even stronger tick repellent!)